the effect of soil parameters on the response of structures subjected to multicomponent earthquake excitation

In order to consider the uncertainty in the ground motion direction with respect to the structure main axes, i.e. incident angle, two simplified approaches have been followed by designers: 1) considering 100% of seismic force in one directionsuperimposed by a percentage, e.g. 30% or 40% of the prescribed force in the orthogonal direction, i.e. so-called 100/30 or 100/40 rules (aashto, 2010); 2) computing the response of a structure for 100% of seismic force in two orthogonal directions and calculating the maximum probable response by square root of the sum of the squares (srss) method (wilson et al., 1995).